Dealer Ponds Norway


I was contacted with regards to building a dealer setup in Norway. The greenhouse frame and excavation was carried out prior to my arrival. The ground is made up of rock and the excavation was done with dynamite. A single concrete base was to cast on to the solid rock and therefore the bottom drains were placed on individual bases to ensure they are placed level. Planning was critical as 3 ponds were to be built with 2 of them running at identical water level and filters placed at the same level in a central area. The third pond was to be raised out of the ground with a single drain to show a formal raised pond. The largest pond is to be a japanese stlye rock pond with 3 drains and the remaining pond is a 2 drain system built in the stlye of a typical garden pond with stone edging. Nothing has been set in 'stone' and the plans may change as the ponds progress. Pond volume of the 3 ponds will be around 13,000 gallons 5,500 gallons and 4000 gallons.



All 4" pipelines have been set level and the pipes located to allow a small gap between each of the filtration units. The airlines have been brought together from the 2 larger ponds and space allowed for any non return valves between pipes. A 120 lpm airpump will feed the 3 air diffusers on the large pond and a 80 lpm airpump will feed the 2 air diffusers on the other in ground pond. Formwork has been placed to mark out where the concrete base is to be cast.



Steel reinforced mesh is used for the base and the concrete will also be a C35 mix with plenty of fibres in. The bottom drains have been stuffed with newspaper and sticky tape placed over the top to prevent concrete from accidently going in. 



The concrete is pumped in and the bases levelled with a large float. Metal rods are then set in the concrete according to where the walls will sit as they too will be formed out of concrete.



The formwork is put together and reinforced with steel in the cavity ready for more concrete to be poured. The walls are going to be 15cm thick and water level has been determined at 150cm.



The walls have now been poured and the formwork removed the following day. Steel rods are placed to tie a concrete shelf for rocks after the area has been backfilled. The corners will be rounded off with concrete block and 2 skimmers will be placed when the shelf is cast. Work now stops on this pond and continues with the other 2 ponds.



The formwork has now been completed on the 5500 gallon pond ready for the concrete to be poured. Water level in this pond is identical to the first pond but without the rock shelf. Its heavy work moving all the formwork and alot of hammering is involved too.


I am putting a special oil on the formwork to prevent the concrete sticking to it. This helps alot when you have to prise them apart the next day.


The concrete is pumped into the formwork for pond number 2.


c10.jpgThere was some leftover concrete so I used it to bench the corners of the first pond and over the next few days I will use concrete block to round the corners off. One of the pond returns is visible in the corner of the pond.



Pond number 2 formwork has been removed and now I can start on pond 3 which will have the concrete poured in a few days along with the concrete base for the 3 quarantine ponds which will be around 3000 gallons each and double as a Tosai room in mid summer when all koi are out of quarantine.



Pond number 3 formwork ready for the concrete. This pond is 3.1m x 3.72 and 2m deep so will hold around 5000 gallons.


This is the area that has been cleared ready for the 3 quarantine/ Tosai ponds. There will be a permanent wall seperating the main pond and the quarantine area.


I have started building the curved walls in the corners and this along with the irregular shaped rocks on the top will help diguise the box shape. Once the curved walls are built I will back fill them with any leftover concrete.


The concrete has been poured for pond number 3 and I have set the drains for the 3 quarantine ponds. Next I will be reinforcing the base of the 3 ponds with steel mesh and concrete will be poured again tomorrow. So far I have poured 32 cubic metres of concrete and by the time I leave that figure will be close to 50.


The concrete has been poured as one base for the 3 quarantine ponds.


Extra concrete was ordered so the corners and slope could be finished in the main pond. All that is left to do is brick the corners up to the top after installing the return pipework.


Pond number 3 after the formwork has been removed from the inside and concrete added to form a slope to the bottom drain.
Pond number 2 with the concrete slopes. The corners need to be rounded off yet with concrete block. The slopes on all the ponds is roughly 10cm high by 50cm so 1 in 5 fall. This will aid debris to be directed to the bottom drains.


The formwork for the quarantine ponds is ready for the concrete. The size of the perimeter wall is 8.1 metres x 2.5 metres and this will be divided afterwards to make 3 identical ponds.